BARCELONA (Reuters) -- Defending world champion Valentino Rossi, riding a Yamaha, finished fastest in Friday's afternoon practice session for Sunday's Catalan Grand Prix.

The Italian, who is fifth in the MotoGP standings, clocked a lap time of 1:42.837 on the Montmelo circuit where he has won on his previous two visits.

American Kenny Roberts, riding a KR211V, was fastest in the morning but trailed Rossi by 0.093 seconds in the second session.

Local rider Dani Pedrosa, on a Honda, came in third, 0.199 seconds off the leader's time, and Australia's Chris Vermeulen on a Suzuki was 0.272 seconds further back in fourth.

Championship leader Loris Capirossi trailed in eighth, 0.596 seconds behind compatriot Rossi, while second-placed Nicky Hayden was eleventh fastest.

In the 125cc category, Finland's Mika Kallio took provisional pole ahead of Thomas Luethi in a rain-interrupted session.